class A:
    def __init__(self):
        print("A")


class B(A):
    def __init__(self):
        print("B")
        super().__init__()


class C(A):
    def __init__(self):
        print("C")
        super().__init__()

class D(B,C):
    def __init__(self):
        print("D")
        super().__init__()


d = D()
print(D.__mro__)